Thank you for contacting Syncfusion support.
We have already discussed about on this and published the knowledge base documentation for this. Please refer to the knowledge base documentation,
We can also use the toolbar template for customize the toolbar items. Please refer to the online sample,
Note: We can perform the operation like add, edit, export, etc.… by using toolbarClick event in the Grid when we use the toolbar template. Refer to the Help document for this event,
Please let us know if you have any concern about this.